Resource Changes method call does not return any 'Create' changes. Under the documentation for resource changes an example of a resourceChanges API call for a new storage account is given. Here it displays what the JSON response will look like, showing multiple changes including a 'Create' change type. I have been unable to replicate this functionality from my end.
Only 'Delete' and 'Update' changes are returned in the call, meaning this functionality is incomplete and not as advertised. Confirmed by one of Azure's Python SDK devs that this is a service issue and that the API call is broken.